Short summary

Acute Myocardial Infarctions affects 2500 persons in Denmark every year. Quick revascularisation therapy is the most important factor in avoiding complications and death. Earlier studies have shown that nearly 50% of patients wait over 2 hours from symptom onset before contacting the healthcare system. This project investigates the causes of this delay, along with the development in the field since 2003. Data is collected through patient interviews as well as patient charts and registers.

Rationale

ST-elevation Myocardial Infarctions (STEMI) affects 2500 persons in Denmark every year. The time from symptom onset to revascularisation therapy is vital for a good treatment result. Longer time between symptom onset and re-establishment of the blood flow to the heart increases the risk of complications including cardiac arrest, heart failure, ventricular septal defects, mitral insufficiency, free wall rupture, death etc.

The time from symptom onset to revascularisation therapy is divided in to:

1) The time from when the patients experience the first symptom of acute myocardial infarction (AMI) until the healthcare system is alerted. This is called the patient delay.

2) The time from first medical contact until the revascularisation therapy is initiated. This is called system delay.

Restructuring of the pre-hospital organisation in Denmark with rapid allocation of ambulances and medical car to patients with chest pain, 12-lead TELE-ECG, transport with medical helicopter over longer distances directly to 24/7 manned cardiology laboratories, has led to a big reduction in system delay over the last 12 years. This has led to a reduction in complication rates and increased survival.

Despite numerous patients aimed information campaigns focusing on recognition of AMI-symptoms, no corresponding improvement of the patient delay has been observed in the same period. The scope of the problem is inadequately described and factors impacting the delay time is unknown. These lacks have obstructed proper aiming of former campaigns that have therefor not lived up to their full enlightenment potential.

If the time from symptom onset to revascularisation is to be reduced further, a reduction of the patient related part of the delay seems to be crucial. A way of achieving this could be through identification of factors influencing patient delay times, so that future information activities can be aimed at population groups with the biggest needs.

Clinical factor's effect on patient delay times has been partly investigated earlier, but factors such as lifestyle, perception and thoughts prior to medical contact lacks clarification. Multiple information campaigns have been conducted since the latest danish record was made, and there have been major changes in both the patient composition, alarm centres and prehospital organization. This necessitates new research in the field, both to assess the clinical and non-clinical factors affecting patient delay times, and the development in the field. It should also be considered to initiate a continuous monitorisation of patient delay times going forward, as part of a quality assessment and as a support to future information campaigns.

This study contains, unlike previous studies, information on the patients own perception of symptom onset, types of symptom and lifestyle, as well as thoughts and considerations in the time leading up to medical contact. The information is obtained through direct patient interviews and supplemented with information gathered from registers and patient charts.

The aim of this study is to clarify the scope of patient delay in patients suffering from STEMI, and to identify population groups with an increased risk of prolonged patient delay. The study is expected to provide a truer picture of the extend and causes of patient delay in 2021.

Numerous factors with potential effect on patient delay times will be investigated, including sex, marital status, social class, distance from place of residence to a major hospital and misperception of symptoms as other diseases.

Should the study show a significant increase in patient delay time among some populations, then that knowledge could be used as a foundation for targeted and more effective information campaigns and education for these people. This research therefor has the potential to increase survival among STEMI-patients both acute and long-term as well as reduce the morbidity of these patients in the years post STEMI.

Hypotheses

- The average patient delay time among STEMI-patients is over 120 minutes.

- Female STEMI-patients have longer patient delay times compared with male STEMI-patients.

- STEMI-symptoms are often interpreted as symptoms of other diseases, including covid-19.

Description of the cohort

All patients with the diagnosis of STEMI, admitted to the Department of Cardiology at Odense University Hospital between March 1st 2021 and September 30th 2021. The patients are identified prospectively through admission charts.

Inclusion criteria:

- 18 years of age or older.

- Clinical symptoms of acute myocardial ischemia (e.g. Chest pain, dyspnoea, acute heart failure or arrythmia).

- ECG with ST-segment elevations or STEMI equivalents.

- At least 1 cardiac marker (Troponin T) over the 99-percentile, as well as dynamics in the marker (elevation/reduction > 20%).

- Identification of obstructed coronary vessel via acute coronary arteriography (CAG).

- Willingness to participate in an interview no later than 21 days after the CAG.

Exclusion criteria

- Incompetent.

- Cognitively impaired, memory impaired or aggressive behaviour.

- Longer admissions to the intensive care unit (ICU) (> 24 hours).

- Loss of consciousness before contact to the health care system.

- Development of STEMI under the hospitalization for other illness.

- Deceased at the time of interview.

- Missing informed consent.

Additionally, this study also uses register data of all STEMI-patients in Western Denmark between 2016-2020. The data is collected retrospectively from the Wester Denmark Heart Database.

Data and biological material

Questionnaire data, data form patient charts, data from the Western Denmark Heart Database.